JP2007102578A - Apparatus and method for distance calculation, and vehicle having the apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distance calculation apparatus capable of calculating the distance to a predetermined position in front with high accuracy, while running on a road. <P>SOLUTION: A transmitter unit 2 is provided on a road R, and also, a white line 7 is provided on the road surface. The distance calculation apparatus includes a reception means 3 for receiving information from the transmitter unit 2, a target recognition means for imaging and recognizing the white line 7, and a distance calculation means for calculating the distance to a stop line P. The reception means 3 receives distance information from the white line 7 to the stop line P. The target recognition means recognizes the white line 7, and the distance calculation means calculates the distance to the stop line P, based on a relative position to the white line 7 and the distance information. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a distance calculation device and method for calculating a distance to a predetermined position ahead while traveling on a road, and a vehicle having the distance calculation device.

Conventionally, in order to prevent traffic accidents caused by vehicles (automobiles) in and near the intersection, the red, yellow and blue display information of the traffic lights provided at the intersection is transmitted wirelessly to the traveling vehicle, There is a device that determines whether or not the intersection can be safely passed based on the information on the vehicle side, and performs operation control based on the determination (see, for example, Patent Document 1).
In the device described in Patent Document 1, for example, time information until a traffic light displaying blue turns red is transmitted to a vehicle by radio from a transmission device provided on the road, and this time information and When it is determined that there is no time to safely pass through the intersection, the vehicle is automatically braked and the vehicle is decelerated and stopped to stop it before the intersection. .

Japanese Patent No. 2806801

However, in the apparatus described in Patent Document 1, when it is necessary to stop the vehicle at the stop line before the intersection, the distance to the stop line cannot be accurately determined even if the vehicle is controlled to decelerate. This makes it difficult to stop the vehicle appropriately according to the stop line, and may cause problems such as overrun. Therefore, the conventional technology is insufficient as a device for preventing accidents at intersections.
On the other hand, since the current running position can be detected by the function of the car navigation system using GPS, if the position of the intersection can be extracted from the map data of the car navigation system, the distance to a predetermined position such as a stop line before the intersection can be calculated. Can do. However, since the position detection error by GPS is at least about 10 m, an error also occurs in the calculated distance, making accurate control difficult.

  Accordingly, in view of the conventional problems as described above, an object of the present invention is to provide a distance calculation apparatus and method capable of accurately calculating the distance to a predetermined position ahead while moving on a road. To do. An object of the present invention is to provide a vehicle capable of controlling the traveling speed based on the calculation of the distance and stopping at the predetermined position or decelerating to the predetermined traveling speed.

  The distance calculation device of the present invention calculates the distance to a predetermined position in the moving direction while moving on the road using information transmitted from a transmission device provided on the road and a target provided on the road. A distance calculating device for receiving distance information from the target to the predetermined position transmitted from the transmitter, a target recognizing unit for recognizing the target, and the target recognizing unit. And a distance calculating means for calculating a distance to the predetermined position based on the relative position and the distance information.

  In the distance calculation method performed by this device, distance information from the target to the predetermined position is transmitted from the transmission device, the distance information is received, the target is recognized while moving, and recognized. A relative position with respect to the target is obtained, and a distance to the predetermined position is calculated based on the relative position and the distance information.

  According to such a distance calculation device and method, the receiving means receives the distance information from the target provided on the road to the predetermined position ahead of the road, and further recognizes the target, A relative position with respect to the target can be obtained, and a distance to the predetermined position can be calculated based on the relative position and the received distance information. Since the distance to the predetermined position is calculated based on the position of the target provided in advance, the distance can be obtained with high accuracy.

In the distance calculation device, the target object recognition means includes an image pickup means for acquiring the target object as an image, and an image processing means for recognizing the target object based on an image from the image pickup means. In this case, the distance calculating means can determine the relative position with respect to the target by operating the imaging means while moving on the road, and the image processing means recognizes the target by processing this image. The distance can be calculated.
Alternatively, in the distance calculation apparatus, the target object recognition unit includes an electromagnetic detection unit that detects a change in the electromagnetic field caused by the target that may cause a change in the electromagnetic field. In this case, while moving on the road, the electromagnetic detection means detects the change of the electromagnetic field caused by the target, so that the target can be recognized, and the distance calculation means obtains the relative position with respect to the target. The distance can be calculated.

In the distance calculation device, the receiving unit further receives information on the approximate distance to the target transmitted from the transmission device, and the distance calculation unit further receives information on the approximate distance. Control means is further provided for calculating a movement distance and causing the target object recognition means to function when the calculated movement distance substantially matches the approximate distance.
According to this configuration, when the receiving unit receives information on the approximate distance to the target, the distance calculating unit can know the approximate distance from the received position to the target. Then, the distance calculating means calculates the moving distance from when the information is received, so that the moving distance can be compared with the approximate distance. Can function. Therefore, even if an object that is confused with the target exists between the position near the target after receiving the signal from the transmission device, the target recognition means prevents the target recognition means from recognizing it incorrectly. Can do.

The vehicle of the present invention is detected by the distance calculation device, speed detection means for detecting a traveling speed, the distance to the predetermined position calculated by the distance calculation means of the distance calculation device, and the speed detection means. Travel control means for controlling the travel speed so that the predetermined speed is reached at the predetermined position based on the travel speed.
According to this configuration, based on the distance to the predetermined position calculated by the distance calculating unit and the traveling speed of the vehicle detected by the speed detecting unit, the traveling control unit controls the traveling speed, thereby The vehicle speed at the position can be set to a predetermined value.

Further, in this vehicle, the receiving means included in the distance calculating device receives the appropriate traveling speed information at the predetermined position transmitted from the transmitting device, and the traveling control means includes the appropriate traveling speed information. Based on this, the traveling speed is controlled so that the appropriate traveling speed is obtained at the predetermined position.
According to this configuration, the traveling control means can control the traveling speed to obtain an appropriate traveling speed at the predetermined position. For example, if the starting point of a curve (curved road) following the road is set as the predetermined position and the curve approach speed for safely driving the curve is set as an appropriate traveling speed, the traveling control means can start the curve at the starting point. The vehicle can be decelerated to an appropriate travel speed and can safely pass the curve.

The travel control means includes correction means for correcting the appropriate travel speed information received by the reception means according to vehicle characteristics, and the travel control means travels based on the corrected proper travel speed information. It controls the speed.
According to this, even when the vehicle has a high vehicle center of gravity and travel stability is lower than that of a normal vehicle, the correction means can correct the appropriate travel speed according to the vehicle characteristics, and safe travel Is possible.

  According to the present invention, distance information from a target to a predetermined position ahead can be received, and the distance to the predetermined position can be accurately known by recognizing the target provided on the road. As a result, the traveling speed at the predetermined position in the vehicle can be controlled to a predetermined value, and safe traveling is possible.

Hereinafter, embodiments of a distance calculation apparatus and method according to the present invention and a vehicle including the distance calculation apparatus will be described with reference to the drawings.
FIG. 1 is a side view of an intersection A with a traffic light 10 and a road R upstream from the intersection A. In addition to the traffic light 10, the road R is provided with a transmission device 2 that wirelessly communicates various types of information to the traveling vehicle C. The transmission unit 2a of the transmission device 2 is attached to a pillar erected at a position upstream of the road R (right side in FIG. 1) by a predetermined distance from the intersection A. Examples of such a transmission device 2 include an optical beacon and a radio beacon. Information transmitted from the transmission device 2 is received by a receiving means (antenna) 3 mounted on the vehicle C.

Further, the road R is provided with a target 7 that is used to calculate the distance to the predetermined position P ahead in the traveling direction while traveling on the vehicle C. The target 7 in FIG. 1 is a white line drawn on the road surface, and the white line 7 is drawn extending in the crossing direction of the road R. Therefore, the vehicle C traveling on the road R passes on the white line 7.
The white line 7 is provided on the intersection A side (downstream side) with respect to the transmission unit 2 a of the transmission device 2. In addition, the white line 7 should just be the intersection A side rather than the upstream edge part of the communication area | region by the transmitter 2 in the road R. FIG.
The predetermined position P is a stop line drawn on the road R before the intersection A. Thus, the vehicle C stops according to the stop line P when the traffic light 10 at the intersection A is displayed in red.

  The distance calculation device according to the present invention is mounted on the vehicle C traveling on the road R. The distance calculation device 1 travels on the road R while traveling on the road R using various information transmitted from the transmission device 2 provided on the road R and the white line 7 provided on the road R. The distance to the stop line P ahead in the direction is calculated.

FIG. 2 is a block diagram showing an outline of the distance calculation device 1 and other devices mounted on the vehicle C.
In FIG. 2, the distance calculating device 1 includes a receiving unit 3 that receives information transmitted by radio from the transmitting device 2, a target recognition unit 4 that recognizes the white line 7, and the stop line P before the intersection A. Distance calculating means 5 for calculating the distance up to.
Various information received by the receiving means 3 is input to the distance calculating means 5. The target object recognition unit 4 transmits and receives signals to and from the distance calculation unit 5 via a control unit 6 that controls the operation of the target object recognition unit 4.
Information transmitted from the transmission device 2 and received by the receiving means 3 includes distance information from the white line 7 to the stop line P. This distance information is data stored in advance on the transmission device 2 side, which is obtained by actual measurement when the white line 7 and the stop line P are provided, and is information having an accurate distance between each other. It is.

  In FIG. 2, the target recognition unit 4 includes an imaging unit 11 and an image processing unit 12 that receives a signal from the imaging unit 11. The imaging unit 11 is an in-vehicle camera that acquires an image, and the image processing unit 12 processes an image from the camera 11. As a result, while the vehicle C is traveling in the upstream position away from the white line 7 (the position of the arrow x in FIG. 1), the camera 11 and the image processing means 12 recognize the road surface of the asphalt on the road R. When the vehicle C travels to a position where the white line 7 falls within the field of view of the camera 11 and the camera 11 acquires the white line 7 as an image (position of the arrow y in FIG. 1), the image processing means 12 is based on the image from the camera 11. The white line 7 is recognized. Note that the image processing means 12 and the image processing in the image processing means 12 can be conventionally known. For example, the white line 7 can be recognized based on the luminance of the image from the camera 11.

Furthermore, as information transmitted from the transmission device 2 and received by the receiving means 3, there is information on the approximate distance to the white line 7. When the transmission device 2 is an optical beacon, the communication range is wide, and therefore the distance between the current travel position of the vehicle C and the white line 7 when the signal is received from the transmission device 2 is large and the error is large. Because of the approximate distance.
Then, the receiving means 3 receives this approximate distance information and the distance calculating means 5 inputs the information. When information is input to the distance calculation means 5, the distance calculation means 5 uses the speed information from the speed detection means 8 mounted on the vehicle C, and the distance calculation means 5 receives the travel distance (reception) Cumulative distance actually traveled from time) is calculated. The distance calculation means 5 compares the calculated travel distance with the approximate distance previously received, and it is possible to detect that the vehicle has traveled to a position just before the white line 7 when the values of the two approximately coincide ( Hereinafter, it is referred to as a function for detecting the position in front of the target. When it is detected that the vehicle has traveled to a position in front of the white line 7, the control means 6 causes the target recognition means 4 to function. That is, by the action of the control means 6, the camera 11 and the image processing means 12 do not function until the position near the white line 7 is reached, and when the position near the white line 7 is reached, they function to recognize the white line 7. Let it begin. As a result, even if a line confusing with the white line 7 exists on the road surface from the position where the signal is received from the transmission device 2 to the position immediately before the white line 7, the image processing unit 12 erroneously recognizes it. Can be prevented.

The distance calculation means 5 is composed of a microcomputer and performs various calculations and processes. Specifically, when the target recognition unit 4 recognizes the white line 7, the distance calculation unit 5 calculates the distance from the current travel position to the stop line P when the distance calculation unit 5 is performing arithmetic processing. To do. This calculation is performed by obtaining a relative position (relative distance) between the current travel position of the vehicle C and the white line 7 when the target recognition unit 4 recognizes the white line 7 and the distance calculation unit 5 performs the calculation process. This is performed based on the obtained relative position and the distance based on the distance information received by the receiving means 3. That is, the distance from the current travel position of the vehicle C to the stop line P is easily obtained by the sum of the relative position (relative distance) with the white line 7 and the distance based on the distance information received by the receiving means 3.
The relative position between the current traveling position of the vehicle C and the white line 7 is a distance in a direction parallel to the road surface between the distance calculation device 1 and the white line 7. With respect to this value, the position of the white line 7 in the screen by the camera 11 is recognized by image processing, and the recognition result, the depression angle of the camera 11, the focal length of the camera 11, and the road surface of the camera 11 are recognized. Can be calculated by the distance calculating means 5 using parameters such as the height dimension.

An example of means for obtaining the relative position of the white line 7 from the position of the white line 7 in the screen by the camera 11 will be described. The camera 11 is set and attached so that a road surface ahead of the front end of the vehicle C can be imaged. The camera 11 is fixed, and the center axis of the lens is set to a fixed direction during image processing. In addition, as a specification of the camera 11, the size of the imaging unit is, for example, a fixed size in which the CCD size is not variable, and the lens has a fixed focal length. That is, the lens is not a zoom lens, or even if it is a zoom lens, the focal length is determined at the time of image acquisition / processing.
Specific means are as follows. As shown in FIG. 10A, the vehicle width direction of the vehicle C is defined as the x-axis direction, and the axial direction (traveling direction) of the vehicle center orthogonal to the vehicle width direction is defined as the y-axis direction.
Since the camera 11 is installed at a predetermined position of the vehicle C and is directed in a certain direction, the y-axis direction distance to the position on the road corresponding to an arbitrary point on the screen by the camera 11 is uniquely determined. Therefore, the distance can be calculated by assigning a distance in the y-axis direction at an arbitrary point on the screen by geometric calculation. However, since there are not a few errors (aberrations) in the imaging device and lens of the camera 11, it is preferable to assign the y-axis direction distance to any one point on the screen by the following experimental means.
As shown in FIG. 10B, a vehicle C on which the camera 11 is mounted is placed on a certain road surface, and a predetermined distance (for example, 1 m, 2 m) from the vehicle front end parallel to the straight line parallel to the y axis and the x axis on the road surface. ) Draw a straight line at a distance. When this road surface is imaged by the camera 11, a screen as shown in FIG. 11A is obtained. The position of the straight line at a distance of 1 m and 2 m on the screen is the position of 1 m and 2 m on the screen. As shown in FIG. 11B, the straight line on the screen and its extension line are set and stored as the straight lines f1 and f2 on the screen, respectively. Thereby, an arbitrary point on the straight line f1 on the screen is 1 m from the vehicle C, and an arbitrary point on the straight line f2 is 2 m from the vehicle C. Also, other distances can be set by the same operation. Thus, by using the straight lines f1 and f2 set and stored in advance, the distance in the y-axis direction to the position on the road corresponding to an arbitrary point on the screen obtained by the camera 11 can be obtained. The relative distance (y-axis direction distance) between the white line 7 and the vehicle C can be calculated from the position of the white line 7 on the screen.

In the distance calculation method performed by the distance calculation device 1 having the above configuration, first, distance information from the white line 7 to the stop line P is transmitted from the transmission device (light beacon) 2 provided away from the intersection A on the upstream side. Then, the receiving means 3 mounted on the vehicle C traveling on the road R toward the intersection A receives this distance information. Thereafter, the vehicle C continues to travel and recognizes the white line 7 while traveling by the camera 11 and the image processing means 12 mounted on the vehicle body. Then, the distance calculation means 5 recognizes the white line 7 as the target, and the target recognition means 4 recognizes the current travel position of the vehicle C and the white line 7 when the distance calculation means 5 is performing arithmetic processing. Is obtained by calculating the distance from the current travel position to the stop line P based on the relative position and the received distance information.
Thus, the vehicle C side receives the distance information from the stop line P to the white line 7 obtained in advance before the intersection A, and further recognizes the white line 7 as an alignment line using the received distance information. Thus, the distance from the current travel position to the stop line P can be calculated with high accuracy.

Next, the vehicle C according to the present invention on which the distance calculation device 1 as described above is mounted will be further described.
In FIG. 2, the vehicle C further includes speed detection means 8 that detects a travel speed and travel control means 9 that controls the travel speed. The speed detection means 8 has a vehicle speed sensor, and transmits a signal about the travel speed to the distance calculation means 5 and the travel control means 9. Thereby, the distance calculation means 5 can calculate the distance traveled from a certain point (cumulative distance) based on the speed information from the speed detection means 8. Furthermore, when the distance from a certain point to a predetermined position ahead is known, the remaining distance to the predetermined position when the certain point is set as the starting point can be calculated. That is, when the distance from a certain point to the front stop line P is calculated and known by the distance calculating means 5, the remaining distance to the stop line P when the certain point is the starting point can be calculated. . As the speed detection means 8 and the vehicle speed sensor, those conventionally known can be used.

Based on the speed information of the vehicle C from the speed detection means 8, the travel control means 9 can control the travel speed so as to be a predetermined speed. That is, the traveling control means 9 can cause the driving means (engine) 15 and the braking means (brake) 16 of the vehicle C to perform acceleration and deceleration operations. The traveling control means 9 is composed of a microcomputer and can be an ECU.
In the case of FIG. 1, based on the distance from the current travel position of the vehicle C calculated by the distance calculation means 5 to the stop line P and the travel speed detected by the speed detection means 8, the travel control means 9 Thus, the traveling speed is controlled so that the speed of the vehicle C becomes zero. That is, based on the distance to the stop line P calculated by the distance calculation means 5, the stop associated with the travel of the vehicle C by the information communication among the distance calculation means 5, the speed detection means 8 and the travel control means 9. While the distance calculation means 5 obtains the remaining distance to the line P as needed, the traveling control means 9 gradually decelerates the vehicle C in the section up to the stop line P and automatically stops at the stop line P accurately. That is, since the vehicle C can accurately calculate the distance to the stop line P by mounting the distance calculation device 1, the position relative to the stop line P for automatic stop at the front stop line P. The alignment operation can be performed with high accuracy.

FIG. 3 sequentially illustrates the driving support operation from the signal reception to the stop performed in the vehicle C, and this method will be described with reference to FIGS.
In FIG. 1, various signals are transmitted from a transmission device (optical beacon) 2 provided at a predetermined distance upstream from the intersection A, and mounted on a vehicle C traveling on the road R toward the intersection A. The receiving means 3 receives this information (step S1 in FIG. 3). In addition, the vehicle C is receiving information at the position of the arrow x in FIG. As signals received by the vehicle C, there are already described “distance information from the white line 7 to the stop line P” and “information of the approximate distance to the white line 7”. Furthermore, in FIG. There is information (hereinafter referred to as “signal display information”) related to the display of the received traffic light 10. When the distance calculation device 1 determines that the “signal display information” is blue (in the case of “No” in step S2), the vehicle C passes through the intersection A without performing the distance calculation operation. (Step S7).

When the “signal display information” is red or yellow (in the case of “Yes” in step S2), the vehicle C is in the vicinity of the white line 7 by the near-position detection function of the vicinity of the target that the distance calculation means 5 has. When it is detected that the front position has been reached, an alignment operation for the stop line P in the vehicle C is started (step S3). In the operation (step S4), the target recognizing means 4 is first caused to function by the control means 6, and the camera 11 and the image processing means 12 take an image of the road surface while the vehicle C is traveling, and the white line 7 provided on the road surface. Recognize Then, by recognizing the white line 7, the distance calculation device 1 calculates the distance, and performs an alignment operation with respect to the stop line P before the intersection A. That is, the current travel position (position of arrow y) of the vehicle C when the target recognition means 4 recognizes the white line 7 and the distance calculation means 5 is performing calculation processing is used as the starting point of the distance to the stop line P. Based on the relative position between the starting point and the white line 7 and the already received “distance information from the white line 7 to the stop line P”, the sum of the distances between the two points is taken to stop the stop line P from the starting point. Is calculated (step S5). Using this calculation result, the traveling control means 9 decelerates the vehicle C and automatically stops the vehicle C according to the stop line P before the intersection A (step S6). The position of the arrow z is the stop position of the vehicle C.
As described above, since the distance calculation device 1 can accurately calculate the distance to the stop line P by performing alignment using the target (white line) 7 provided in advance on the road R, based on this calculation result. Thus, the vehicle C can be automatically stopped according to the stop line P with high accuracy, and excellent safe driving support is possible.

  As a comparative example, for example, the received signal from the optical beacon is “distance information from the position where the signal was received from the optical beacon to the stop line P”, and the distance based on this distance information is recognized as the distance to the stop line P on the vehicle side. And when it is set as the structure which decelerates a vehicle according to this, since the communication range of an optical beacon is wide (3m), if a shift | offset | difference arises in a receiving position, there is a possibility that the position of the stop line P may be mistaken and overrun. is there. However, as in the present invention, a predetermined distance (white line) 7 that is provided at a predetermined distance from the stop line P is used as a reference, the predetermined distance is received as wireless information, and the position relative to the stop line P is used by using this information. By performing the alignment, the position of the stop line P can be obtained with high accuracy.

  Further, as another embodiment of the driving support operation performed in the vehicle C, step S2 and step S7 in FIG. 3 are omitted, and the alignment operation is performed regardless of the current display state of the traffic light 10 at the intersection A. . That is, with reference to FIG. 1, the receiving means 3 mounted on the vehicle C traveling on the road R toward the intersection A receives information (step S1). There are two types of signals in this case: “distance information from the white line 7 to the stop line P” and “information of the approximate distance to the white line 7”. Then, after receiving this information, if it is detected that the vehicle C has reached the position in the vicinity of the white line 7 by the function of detecting the position in the vicinity of the target that the distance calculation means 5 has, the stop line in the vehicle C is detected. An alignment operation for P is started (step S3). The following operations are the same as those in FIG.

  In FIG. 1, the distance calculation device 1 calculates the distance to the stop line P before the intersection A, and the travel control means 9 has explained the function of automatically stopping the vehicle C with the travel speed set to zero at the stop line P. Other functions of the vehicle C of the invention will be described with reference to FIGS. This function is based on the distance to the predetermined position calculated by the distance calculating means 5 of the distance calculating device 1 and the traveling speed detected by the speed detecting means 8. The traveling speed is controlled so that a predetermined speed is obtained at a predetermined position. That is, this is a function capable of automatically decelerating in advance at a predetermined position in front of the curve so that the vehicle C can safely travel on a curve (curved road).

  Specifically, in FIG. 4, the transmission unit 2a of the transmission device (optical beacon) 2 is provided at a position upstream of the road R (right side in FIG. 4) by a predetermined distance from the starting point Q of the curve B. ing. Further, the road R is provided with a target 7 that is used to calculate the distance to the starting point Q in the traveling direction while traveling on the vehicle C. The target 7 is a white line as in FIG. The white line 7 is provided on the curve B side with respect to the transmission unit 2a of the transmission device 2.

  Various signals are transmitted from the transmission device 2, and the reception means 3 mounted on the vehicle C traveling on the road R toward the curve B receives the signals. Information to be received includes “distance information from the white line 7 to the starting point Q before the curve”, “information of the appropriate traveling speed on the curve”, and “information of the approximate distance to the white line 7”. Among these, “the distance information from the white line 7 to the starting point Q before the curve” and “the information of the approximate distance to the white line 7” are the same as those in the form of FIGS. 1 and the stop line P in FIG. The configuration of the device mounted on the vehicle C is as shown in FIG.

  The distance calculation means 5 included in the distance calculation device 1 mounted on the vehicle C can calculate the distance from the current traveling position of the vehicle C to a predetermined position ahead as described above. In this case, the distance to the starting point Q can be calculated. Further, referring to FIG. 2, the vehicle C includes a speed detection unit 8 that detects a traveling speed and a traveling control unit 9 that controls the traveling speed. Based on the distance to the starting point Q calculated by the distance calculating unit 5 and the traveling speed detected by the speed detecting unit 8, the traveling control unit 9 causes the vehicle C to reach a predetermined speed at the starting point Q. Control to reduce the running speed. The “predetermined speed” is the appropriate traveling speed in the received “information on the appropriate traveling speed on the curve”. This appropriate traveling speed is stored in advance as transmission information in the transmission device 2 provided on the upstream side of each curve B, and the information is transmitted to the vehicle C traveling. The appropriate travel speed is defined as the approach speed at the start point Q for safely traveling the curve B. The appropriate traveling speed is set based on a normal passenger car.

FIG. 5 illustrates the deceleration operation performed in the vehicle C in order, and this method will be described with reference to FIGS. 4 and 5.
The signal is transmitted from a transmission device (optical beacon) 2 provided on the upstream side of the curve B, and the receiving means 3 mounted on the vehicle C traveling on the road R toward the curve B receives this information. (Step S11 in FIG. 5). In addition, the vehicle C is receiving information at the position of the arrow x in FIG. Thereafter, the vehicle C continues to travel, and when the distance calculating means 5 detects that the vehicle C has reached the near front position of the white line 7 (as in the case of FIG. 3), An alignment operation with respect to the starting point portion Q for decelerating the vehicle C so as to achieve an appropriate traveling speed at the starting point portion Q before the curve B is started (step S12).

  The specific operation (step S13) is as follows. When the distance calculation means 5 detects that the vehicle has reached the position near the white line 7, the control means 6 causes the target recognition means 4 to function, The image processing means 12 captures the road surface while the vehicle C is traveling, and recognizes the white line 7 provided on the road surface. Then, by recognizing the white line 7, the distance calculation device 1 calculates the distance and performs a positioning operation with respect to the starting point Q before the curve B. That is, the current travel position (position of arrow y) of the vehicle C when the target recognition means 4 recognizes the white line 7 and the distance calculation means 5 is performing calculation processing is used as the starting point of the distance to the starting point Q. Based on the relative position between the starting point and the white line 7 and the already received “distance information from the white line 7 to the starting point Q before the curve”, the sum of the distances of the two is taken to determine the starting point from the starting point. The distance to the starting point Q is calculated (step S14).

Further, the receiving means 3 included in the distance calculating device 1 receives “appropriate travel speed information on the curve B” in addition to “distance information from the white line 7 to the starting point Q before the curve”. Therefore, the traveling control means 9 controls the traveling speed based on this information so that the starting point Q has an appropriate traveling speed.
Further, the travel control means 9 has a correction means 14 (see FIG. 2) for correcting the appropriate travel speed information according to vehicle characteristics. The correction means 14 has a function of multiplying the appropriate traveling speed of the received appropriate traveling speed information by a coefficient. The coefficient is a value determined in advance according to vehicle characteristics such as the vehicle type of the vehicle C to which the apparatus is attached, and is stored in the correction means 14. The coefficient is, for example, “1”, which is a reference value in the case of an ordinary passenger car, and “0.8” which is smaller than this reference value in the case of a truck having a high vehicle center of gravity and lower running stability than that of an ordinary passenger car. On the contrary, in the case of a sports type automobile having a low vehicle center of gravity and high running stability, it is set to “1.1” which is larger than this reference value. Thereby, for example, when the appropriate traveling speed (speed at the start point Q) on a certain curve B is 40 km / h, the appropriate traveling speed calculated and corrected by the correcting means 14 in the track is 32 km / h, The appropriate traveling speed corrected by the correcting means 14 in the sport type automobile is 44 km / h (step S15). By performing such correction, it is possible to suppress unnecessary deceleration while securing the safety level by controlling the speed, particularly in a sports type vehicle.

Then, on the vehicle C side, based on the distance obtained in step S14, the starting point portion associated with the traveling of the vehicle C by the information communication among the distance calculating means 5, the speed detecting means 8 and the traveling control means 9 While the distance calculation means 5 obtains the remaining distance up to Q as needed, the travel control means 9 controls the travel speed based on the appropriate travel speed information or the corrected proper travel speed information. That is, the traveling control means 9 gradually decelerates in the section to the starting point Q so that the traveling speed of the vehicle C becomes the appropriate traveling speed or the corrected traveling speed at the starting point Q before the curve B (step S16). ). As described above, since the distance calculation device 1 can accurately calculate the distance to the starting point Q before the curve B by performing alignment using the target (white line) 7 provided in advance on the road R, this Based on the calculation result, the vehicle C can be accurately decelerated to the appropriate traveling speed at the starting point Q. As a result, the vehicle can safely pass through the curve B, and excellent safe driving support is possible.
As described above, according to the vehicle C of the present invention, it is possible to automatically stop at the stop line P for the intersection A, and automatically decelerate to a safe approach speed before the curve B. Can do.

FIG. 6 is a diagram showing another embodiment of a vehicle C according to the present invention, and this embodiment has the target 7 shown in FIG. 1 and the distance calculation device 1 shown in FIG. The target recognition means 4 is different. Others are the same as those in FIG. 1 and FIG. Hereinafter, different points will be mainly described.
In FIG. 6, the target 7 is a magnetic marker embedded in the road R. The magnetic marker 7 is provided closer to the intersection A than the transmission unit 2 a of the transmission device 2. And the target recognition means 4 which is a vehicle-mounted side has the detection means 13 which detects the change of the local field by this magnetic marker 7. FIG. 6 illustrates a case where the vehicle C is automatically decelerated and stopped according to a stop line P provided in front of the intersection A as in the case of FIG. FIG. 7 illustrates this operation in order.

Steps S31 to S33, S35 and S36 in FIG. 7 are the same as Steps S1 to S3, Step S5 and Step S6 in FIG. However, the white line in FIG. 3 is replaced with a magnetic marker in FIG. The signals received by the receiving means 3 are “signal display information”, “distance information from the magnetic marker 7 to the stop line P”, and “information of the approximate distance to the magnetic marker 7”.
Referring to FIG. 7, when the signal display information is red or yellow (in the case of “Yes” in step S <b> 32), the vehicle C is detected by the near position detection function of the target that the distance calculation means 5 has. When it is detected that the position near the magnetic marker 7 has been reached, the vehicle C starts an alignment operation with respect to the stop line P (step S33). In the operation (step S34), first, the control means 6 causes the target recognition means 4 to function, and the detection means 13 detects a change in the magnetic field with respect to the road R while the vehicle C is traveling, and is provided on the road R. The magnetic marker 7 is recognized. Then, by recognizing the magnetic marker 7, the distance calculation device 1 calculates the distance, and performs an alignment operation with respect to the stop line P before the intersection A. That is, the current traveling position (position indicated by arrow y) of the vehicle C when the magnetic marker 7 is recognized and the distance calculation means 5 is performing the calculation process is used as the starting point of the distance to the stop line P. Based on the relative position with respect to the magnetic marker 7 and the already received “distance information from the magnetic marker 7 to the stop line P”, the distance from the starting point to the stop line P is obtained by taking the sum of both distances. Is calculated (step S35). In addition, since the detection means 13 mounted on the vehicle C detects the magnetic marker 7 when traveling on the magnetic marker 7, the relative position between the current traveling position and the magnetic marker 7 is The horizontal distance from the front end to the detection means 13, or this horizontal distance is small, so it is determined as zero, or set as zero in advance. Thereby, the distance calculation means 5 can obtain the relative position.

Then, using the calculation result in the distance calculation means 5, the traveling control means 9 decelerates the vehicle C and stops the vehicle C according to the stop line P before the intersection A (step S36). The position of the arrow z is the stop position of the vehicle C.
As described above, since the distance calculation device 1 can accurately calculate the distance to the stop line P by performing alignment using the target (magnetic marker) 7 provided on the road R in advance, Based on this, the vehicle C can be automatically stopped according to the stop line P with high accuracy, and excellent safe driving support becomes possible.

  Further, as another embodiment of the operation for automatically decelerating the vehicle C and stopping according to the stop line P provided before the intersection A as described above, step S32 and step S37 in FIG. 7 are omitted. Then, the alignment operation is performed regardless of the current display state of the traffic light 10 at the intersection A. That is, with reference to FIG. 6, the receiving means 3 mounted on the vehicle C traveling on the road R toward the intersection A receives information (step S31). There are two types of signals in this case: “distance information from the magnetic marker 7 to the stop line P” and “information of the approximate distance to the magnetic marker 7”. Then, after receiving this information, if it is detected that the vehicle C has reached the near front position of the magnetic marker 7 by the function of detecting the near front position of the target that the distance calculating means 5 has, the vehicle C stops. An alignment operation for the line P is started (step S33). The following operations are the same as in FIG.

FIG. 8 is a diagram for explaining other functions provided in the vehicle C shown in FIGS. 6 and 7. In FIG. 8, the target 7 shown in FIG. 4 and the distance calculation device shown in FIG. 1 has different target recognition means 4. Others are the same as those in FIGS. Hereinafter, different points will be mainly described.
In FIG. 8, the target 7 is a magnetic marker embedded in the road R. The target recognition unit 4 includes a detection unit 13 that detects a change in the ground caused by the magnetic marker 7. FIG. 8 illustrates a case where the vehicle is automatically decelerated so as to reach a predetermined speed at the starting point Q before curve B, as in the case of FIG. FIG. 9 illustrates this operation in order.

Steps S41, S42 and steps S44 to S46 in FIG. 9 are the same as steps S11, S12 and steps S14 to S16 in FIG. However, the white line in FIG. 5 is replaced with a magnetic marker in FIG. The signals received by the receiving means 3 are “information on the appropriate traveling speed on the curve B”, “distance information from the magnetic marker 7 to a predetermined position (start point Q) before the curve”, and “to the magnetic marker 7”. Approximate distance information ”.
In FIG. 9, the signal is transmitted from a transmitting device (optical beacon) 2 provided away from the curve B, and the receiving means 3 mounted on the vehicle C traveling on the road R toward the curve B receives this information. Is received (step S41). Thereafter, the vehicle C continues to travel, and when it is detected that the vehicle C has reached the near position near the magnetic marker 7 by the function of detecting the near position of the target that the distance calculation means 5 has, the vehicle C before the curve B is detected. An alignment operation with respect to the start point Q for decelerating the vehicle C so as to reach a predetermined speed at the start point Q is started (step S42).

  The specific operation (step S43) is as follows. When the distance calculating means 5 detects that the vehicle has reached a position in front of the magnetic marker 7, the control means 6 causes the target recognition means 4 to function, thereby detecting means. 13 detects a change in the magnetic field with respect to the road R while the vehicle C is traveling, and recognizes the magnetic marker 7 provided on the road R. Then, by recognizing the magnetic marker 7, the distance calculation device 1 calculates the distance and performs a positioning operation with respect to the starting point Q before the curve B. That is, the current traveling position (position of the arrow y) of the vehicle C when the magnetic marker 7 is recognized and the distance calculation means 5 is performing the calculation process is used as the starting point of the distance to the starting point Q. Based on the relative position with respect to the magnetic marker 7 and the already received “distance information from the magnetic marker 7 to the starting point Q before the curve”, the sum of both distances is taken to obtain the starting point from the starting point. The distance to Q is calculated (step S44).

  The receiving means 3 included in the distance calculating device 1 receives “proper travel speed information on the curve B” in addition to “distance information from the magnetic marker 7 to the starting point Q before the curve”. As in step S15 in FIG. 5, the correction means 14 included in the travel control means 9 corrects the received appropriate travel speed information according to the characteristics of the vehicle C (step S45).

Then, on the vehicle C side, based on the distance obtained in step S44, the starting point portion associated with the traveling of the vehicle C by the information communication among the distance calculating means 5, the speed detecting means 8, and the traveling control means 9 While the distance calculation means 5 obtains the remaining distance up to Q as needed, the travel control means 9 controls the travel speed based on the appropriate travel speed or the corrected proper travel speed. That is, the traveling control means 9 gradually decelerates in the section to the starting point Q so that the traveling speed of the vehicle C becomes an appropriate traveling speed or a corrected appropriate traveling speed at the starting point Q before the curve B (step S46). ). Thus, since the distance calculation device 1 can accurately calculate the distance to the starting point Q before the curve B by performing alignment using the target (magnetic marker) 7 provided in advance on the road R, Based on this calculation result, the vehicle C can be accurately decelerated to the appropriate traveling speed at the starting point Q. As a result, the vehicle can safely pass through the curve B, and excellent safe driving support is possible.
In the present invention, the place where the vehicle C needs to be decelerated to a predetermined speed has been described as the start point Q before the curve B in FIGS. 4 and 8, but this place is not limited to this, and other places on the road It may be the place of.

In the embodiment of FIGS. 1 and 4 in the present invention, the target 7 is a white line displayed on the road surface of the road R and this is used as an alignment line. However, the target 7 is not a white line. Alternatively, a mark such as a circle or a square displayed on the road surface of the road R may be used. That is, the mark only needs to be recognizable as the target 7 by the image processing means 12, and the recognition accuracy is improved by making the shape other than the traffic sign normally displayed on the road R. Can be made.
Further, the target 7 may be other than the one displayed on the road surface of the road R, and may be a sign installed on the road R, a signboard for guidance, or the like. When the target 7 is displayed on the road surface as a white line, the height of the target 7 is zero, so the distance to the target 7 can be calculated by one camera. When 7 is a sign or signboard, it has these height dimensions (because the height is greater than zero), so there are two different points using a stereo camera, two cameras, or a mirror or prism. Such a means is used that a single image is captured. In addition, what is necessary is just to employ | adopt the method currently disclosed by Unexamined-Japanese-Patent No. 7-63573, for such recognition methods, such as a sign on a road R, a signboard, etc., for example.

  Further, in the embodiment shown in FIGS. 6 and 8, the target 7 can change the electromagnetic field in addition to the magnetic marker, for example, there is a coil. In this case, the electromagnetic detection means 13 included in the target recognition means 4 only needs to be able to detect a change in the electromagnetic field caused by the target 7.

  In addition, the safe driving support system including the distance calculation device 1 (vehicle C equipped with the same), the target object 7, and the transmission device 2 according to each of the embodiments is not limited to the illustrated form, However, other forms may be used within the scope of the present invention. For example, the transmitting device 2 may be other than a light / radio wave beacon and may be any device that can communicate information with the vehicle C side by radio.

It is a figure explaining one embodiment of a vehicle carrying a distance calculation device concerning the present invention, and is a figure showing the intersection with a traffic light and the road on the upstream side from the side. It is a block diagram which shows the outline of the distance calculation apparatus mounted in the vehicle, and another apparatus. 2 is a flowchart illustrating an operation of driving support performed in the vehicle of FIG. It is a figure explaining the other function with which the vehicle of FIG. 1 is provided, and is the figure which showed the road upstream of the curve from the side. 5 is a flowchart for explaining an operation of driving support performed in the vehicle of FIG. 4. It is a figure explaining other embodiment of the vehicle carrying the distance calculation device concerning the present invention, and is the figure showing the intersection with a traffic light and the road on the upstream side from the side. FIG. 7 is a flowchart illustrating an operation of driving support performed in FIG. 6. It is a figure for demonstrating the other function with which the vehicle of FIG. 6 is provided, and is the figure which showed the road upstream of the curve from the side surface. It is a flowchart figure explaining the operation | movement of the driving assistance performed in FIG. It is explanatory drawing explaining an example of a means to obtain a relative position with a white line. It is explanatory drawing explaining the means to obtain a relative position with a white line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Distance calculation apparatus 2 Transmission apparatus 3 Reception means 4 Target recognition means 5 Distance calculation means 6 Control means 7 Target object 8 Speed detection means 9 Travel control means 11 Imaging means 12 Image processing means 13 Electromagnetic detection means 14 Correction means A Intersection B Curve C Vehicle P Predetermined position Q Start point R Road

Claims (8)

A distance calculation device that calculates a distance to a predetermined position ahead in the movement direction while moving on the road using information transmitted from a transmission device provided on the road and a target provided on the road,
Receiving means for receiving distance information from the target to the predetermined position transmitted from the transmitting device;
Target recognition means for recognizing the target;
Distance calculating means for obtaining a relative position to the target recognized by the target recognition means and calculating a distance to the predetermined position based on the relative position and the distance information;
A distance calculation device comprising:   The distance according to claim 1, wherein the target recognition unit includes an imaging unit that acquires the target as an image, and an image processing unit that recognizes the target based on an image from the imaging unit. Calculation device.   The distance calculation device according to claim 1, wherein the target recognition unit includes an electromagnetic detection unit that detects a change in the electromagnetic field caused by the target that can cause a change in the electromagnetic field. The receiving means further receives information on the approximate distance to the target transmitted from the transmitting device,
The distance calculating means further calculates a moving distance from when the information on the approximate distance is received,
The distance calculation device according to any one of claims 1 to 3, further comprising a control unit that causes the target recognition unit to function when the calculated moving distance substantially matches the approximate distance. A distance calculation method for calculating a distance to a predetermined position ahead in the movement direction while moving on the road using information transmitted from a transmission device provided on the road and a target provided on the road,
Distance information from the target to the predetermined position is transmitted from the transmission device,
Receive this distance information,
Recognizing the target while moving,
Obtain the relative position to the recognized target,
A distance calculation method comprising calculating a distance to the predetermined position based on the relative position and the distance information. The distance calculation device according to any one of claims 1 to 4,
Speed detecting means for detecting a traveling speed;
Travel control for controlling the travel speed so as to achieve a predetermined speed at the predetermined position based on the distance to the predetermined position calculated by the distance calculation unit of the distance calculation device and the travel speed detected by the speed detection unit Means,
A vehicle characterized by comprising: The receiving means provided in the distance calculating device receives the appropriate traveling speed information at the predetermined position transmitted from the transmitting device,
The vehicle according to claim 6, wherein the travel control unit controls the travel speed so that the travel speed is an appropriate travel speed at the predetermined position based on the proper travel speed information.   The travel control unit includes a correction unit that corrects the appropriate travel speed information received by the reception unit according to vehicle characteristics, and the travel control unit calculates a travel speed based on the corrected proper travel speed information. The vehicle according to claim 7 to be controlled.

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